1. Field of the Invention
The present invention relates to an apparatus for controlling the temperature of a fluid by use of a thermoelectric device that is often called Peltier device.
2. Disclosure of the Prior Art
The destruction of the ozone layer caused by the constant release into the atmosphere of chemicals known as chlorofluorocarbons (CFCs) is a serious problem for the global environment. For example, the CFCs are used as a coolant for conventional refrigerators. From the viewpoint of the global environmental protection, development is going on to fine an alternative to the conventional refrigerators using the CFCs. In recent years, a cooling apparatus using a thermoelectric device that is often called Peltier device has gained attention.
FIG. 16 shows a schematic cross-sectional view of a conventional apparatus for controlling the temperature of a fluid by use of the thermoelectric device. This apparatus comprises a temperature control unit, which is composed of a first heat-transfer member 2S having channels 20S, through which the fluid flows, a pair of thermo-modules 1S each incorporating the thermoelectric device, and a pair of second heat-transfer members 3S each having a flange 30S on its periphery. When an electric current is supplied to the thermo-module 1S of the temperature control unit, one side of the thermo-module acts as a heat absorption means of absorbing heat from the fluid flowing in the channels 20S through the first heat-transfer member 2S, and the opposite side of the thermo-module 1S acts as a heat radiation means of radiating heat toward the second heat-transfer member 3S. Therefore, the temperature control unit is capable of cooling the fluid without using the CFCs.
The temperature control unit is held by use of fixtures 4S such as bolts 41S and nuts 42S. In FIG. 16, the numeral 35S designates a through-hole for the use of the bolt 41S, which is formed in the flange 30S of the second heat-transfer member 3S. After the first heat-transfer member 2S and the thermo-modules 1S are put between the second heat-transfer members 3S, the second heat-transfer members are joined by the bolts 41S and the nuts 42S.
By the way, when the apparatus is operated, a thermal stress occurs in the temperature control unit. Since the temperature control unit rigidly held by use of the bolts 41S and the nuts 42S can not release the thermal stress, there is a problem that the thermo-modules 1S are often broken by the thermal stress. Overtightening the bolts 41S may also lead to a breakage of the thermo-modules 1S. Thus, the apparatus still has plenty of room for improvement.
To solve the above-described problems, the present invention provides an improved apparatus for controlling the temperature of a fluid by use of a thermoelectric device. The apparatus comprises at least one temperature control unit, which is composed of a thermo-module incorporating the thermoelectric device, first heat-transfer member, and a second heat transfer member having a flange on its periphery. The first heat-transfer member has at least one channel, through which the fluid flows. The thermo-module is placed on the first heat-transfer member. The second heat-transfer member is placed on the thermo-module. The temperature control unit is held by use of a case and a cover. The case has an opening, through which the temperature control unit is mounted in the case. The cover is used to close the opening of the case. One of the case and the cover is formed with an aperture for exposing a part of the second heat-transfer member, and a first flange extending around the aperture. The first flange is pressed against the flange of the second heat-transfer member through a sealing material having elasticity. The first heat-transfer member and the thermo-module of the temperature control unit are disposed in an enclosed space between the case and the cover.
In addition, the present invention provides an improved apparatus for controlling the temperature of a fluid by use of a thermoelectric device, as described below. The apparatus comprises at least one temperature control unit, which is composed of a first heat-transfer member, a pair of thermo-modules each incorporating the thermoelectric device, and a pair of second heat-transfer members each having a flange on its periphery. The first heat-transfer member has at least one channel, through which the fluid flows. The thermo-modules are placed on opposite surfaces of the first heat-transfer member. Each of the second heat-transfer members is placed on the thermo-module. The temperature control unit is held by use of a case and a cover. The case has an opening, through which the temperature control unit is mounted in the case. The cover is used to close the opening of the case. The case is formed with a first aperture for exposing a part of one of the second heat-transfer members, and a first flange extending around the first aperture. The first flange of the case is pressed against the flange of one of the second heat-transfer members through a sealing material having elasticity. The cover is formed with a second aperture for exposing a part of the other one of the second heat-transfer members, and a second flange extending around the second aperture. The second flange of the cover is pressed against the flange of the other one of the second heat-transfer members through a sealing material having elasticity. The first heat-transfer member and the thermo-modules of the temperature control unit are disposed in an enclosed space between the case and the cover.
In addition, the present invention provides an improved apparatus for controlling the temperature of a fluid by use of a thermoelectric device, as described below. The apparatus comprises at least one temperature control unit, which is composed of a first heat-transfer member, a pair of thermo-modules each incorporating the thermoelectric device, and a pair of second heat-transfer members each having a flange on its periphery. The first heat-transfer member has at least one channel, through which the fluid flows. The thermo-modules are placed on opposite surfaces of the first heat-transfer member. Each of the second heat-transfer members is placed on the thermo-module. The temperature control unit is held by use of a pair of holding frames each having an aperture. The temperature control unit is held between the holding frames such that each of the holding frames is pressed against the flange of the second heat-transfer member through a sealing material having elasticity, and a part of the second heat-transfer member is exposed through the aperture.
Since the apparatus of the present invention has a structure that the temperature control unit is held by repulsion of the sealing material having elasticity, it is possible to protect the thermo-module(s) from the thermal stress.
These and other objects and advantages will become apparent from the following detailed description of the preferred embodiments of the invention.